// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_FORMATS_WEBM_WEBM_STREAM_PARSER_H_
#define MEDIA_FORMATS_WEBM_WEBM_STREAM_PARSER_H_

#include <stdint.h>

#include <memory>

#include "base/callback_forward.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "media/base/audio_decoder_config.h"
#include "media/base/byte_queue.h"
#include "media/base/media_export.h"
#include "media/base/stream_parser.h"
#include "media/base/video_decoder_config.h"

namespace media {

class WebMClusterParser;

class MEDIA_EXPORT WebMStreamParser : public StreamParser {
public:
    WebMStreamParser();
    ~WebMStreamParser() override;

    // StreamParser implementation.
    void Init(const InitCB& init_cb,
        const NewConfigCB& config_cb,
        const NewBuffersCB& new_buffers_cb,
        bool ignore_text_tracks,
        const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
        const NewMediaSegmentCB& new_segment_cb,
        const EndMediaSegmentCB& end_of_segment_cb,
        const scoped_refptr<MediaLog>& media_log) override;
    void Flush() override;
    bool Parse(const uint8_t* buf, int size) override;

private:
    enum State {
        kWaitingForInit,
        kParsingHeaders,
        kParsingClusters,
        kError
    };

    void ChangeState(State new_state);

    // Parses WebM Header, Info, Tracks elements. It also skips other level 1
    // elements that are not used right now. Once the Info & Tracks elements have
    // been parsed, this method will transition the parser from PARSING_HEADERS to
    // PARSING_CLUSTERS.
    //
    // Returns < 0 if the parse fails.
    // Returns 0 if more data is needed.
    // Returning > 0 indicates success & the number of bytes parsed.
    int ParseInfoAndTracks(const uint8_t* data, int size);

    // Incrementally parses WebM cluster elements. This method also skips
    // CUES elements if they are encountered since we currently don't use the
    // data in these elements.
    //
    // Returns < 0 if the parse fails.
    // Returns 0 if more data is needed.
    // Returning > 0 indicates success & the number of bytes parsed.
    int ParseCluster(const uint8_t* data, int size);

    // Fire the encrypted event through the |encrypted_media_init_data_cb_|.
    void OnEncryptedMediaInitData(const std::string& key_id);

    State state_;
    InitCB init_cb_;
    NewConfigCB config_cb_;
    NewBuffersCB new_buffers_cb_;
    bool ignore_text_tracks_;
    EncryptedMediaInitDataCB encrypted_media_init_data_cb_;

    NewMediaSegmentCB new_segment_cb_;
    EndMediaSegmentCB end_of_segment_cb_;
    scoped_refptr<MediaLog> media_log_;

    bool unknown_segment_size_;

    std::unique_ptr<WebMClusterParser> cluster_parser_;
    ByteQueue byte_queue_;

    DISALLOW_COPY_AND_ASSIGN(WebMStreamParser);
};

} // namespace media

#endif // MEDIA_FORMATS_WEBM_WEBM_STREAM_PARSER_H_
